U.S. patent application number 15/722163 was filed with the patent office on 2019-04-04 for wing-fuselage integrated airframe beams for tiltrotor aircraft.
This patent application is currently assigned to Bell Helicopter Textron Inc.. The applicant listed for this patent is Bell Helicopter Textron Inc.. Invention is credited to Andrew G. Baines, John Elton Brunken, JR., James Everett Kooiman, John Richard McCullough, Brett Rodney Zimmerman.
Application Number | 20190100297 15/722163 |
Document ID | / |
Family ID | 63667701 |
Filed Date | 2019-04-04 |
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United States Patent
Application |
20190100297 |
Kind Code |
A1 |
Brunken, JR.; John Elton ;
et al. |
April 4, 2019 |
Wing-Fuselage Integrated Airframe Beams for Tiltrotor Aircraft
Abstract
An airframe for a tiltrotor aircraft includes a wing airframe
including a rib, a fuselage airframe including a fore-aft overhead
beam and a cradle support assembly. The cradle support assembly
includes a forward wing support coupled to the fore-aft overhead
beam and the wing airframe and an aft wing support coupled to the
fore-aft overhead beam and the wing airframe. The rib, the fore-aft
overhead beam, the forward wing support and the aft wing support
are substantially aligned to form a wing-fuselage integrated
airframe beam assembly to support the wing airframe.
Inventors: |
Brunken, JR.; John Elton;
(Fort Worth, TX) ; Baines; Andrew G.; (Fort Worth,
TX) ; Kooiman; James Everett; (Fort Worth, TX)
; McCullough; John Richard; (Fort Worth, TX) ;
Zimmerman; Brett Rodney; (Fort Worth, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bell Helicopter Textron Inc. |
Fort Worth |
TX |
US |
|
|
Assignee: |
Bell Helicopter Textron
Inc.
Fort Worth
TX
|
Family ID: |
63667701 |
Appl. No.: |
15/722163 |
Filed: |
October 2, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64C 1/1407 20130101;
B64C 29/0033 20130101; B64C 27/28 20130101; B64C 1/061 20130101;
B64C 1/064 20130101; B64C 27/26 20130101; B64C 1/26 20130101; B64C
3/187 20130101; B64C 3/185 20130101 |
International
Class: |
B64C 1/26 20060101
B64C001/26; B64C 1/06 20060101 B64C001/06; B64C 3/18 20060101
B64C003/18; B64C 29/00 20060101 B64C029/00 |
Claims
1. An airframe for a tiltrotor aircraft comprising: a wing airframe
including a rib; a fuselage airframe including a fore-aft overhead
beam; and a cradle support assembly including a forward wing
support coupled to the fore-aft overhead beam and the wing airframe
and an aft wing support coupled to the fore-aft overhead beam and
the wing airframe; wherein, the rib, the fore-aft overhead beam,
the forward wing support and the aft wing support are substantially
aligned to form a wing-fuselage integrated airframe beam assembly
to support the wing airframe.
2. The airframe as recited in claim 1 wherein the wing airframe
further comprises a forward spar, an aft spar, a top skin, a bottom
skin and a plurality of ribs to form a torque box structure.
3. The airframe as recited in claim 1 wherein the fuselage airframe
further comprises a side wall and wherein the wing-fuselage
integrated airframe beam assembly forms a generally vertical plane
with the side wall of the fuselage airframe.
4. The airframe as recited in claim 1 wherein the fuselage airframe
forms a door opening at least partially underneath the wing
airframe.
5. The airframe as recited in claim 4 wherein the door opening has
a forward edge and an aft edge and wherein the cradle support
assembly extends at least as forward as the forward edge of the
door opening and at least as aft as the aft edge of the door
opening.
6. The airframe as recited in claim 4 wherein the door opening has
a forward edge and an aft edge and wherein the cradle support
assembly extends forward of the forward edge of the door opening
and aft of the aft edge of the door opening.
7. The airframe as recited in claim 1 wherein the fuselage airframe
has outboard edges; and wherein the wing airframe further comprises
a plurality of ribs spaced spanwise along the wing airframe, the
rib of the wing-fuselage integrated airframe beam assembly
proximate one of the outboard edges of the fuselage airframe.
8. The airframe as recited in claim 1 wherein the cradle support
assembly further comprises wing contour ridges protruding
vertically from the fore-aft overhead beam.
9. The airframe as recited in claim 8 wherein the wing contour
ridges are integral with the fore-aft overhead beam.
10. The airframe as recited in claim 1 wherein the cradle support
assembly further comprises one or more shear ties coupling an
underside of the wing airframe to the fore-aft overhead beam.
11. The airframe as recited in claim 1 wherein the wing airframe
further comprises a top skin, wherein the cradle support assembly
has a top side forming a beam cap and wherein the cradle support
assembly further comprises one or more support straps coupling the
beam cap to the top skin.
12. The airframe as recited in claim 1 wherein the cradle support
assembly has a top side and the wing airframe further comprises a
top skin, the top side of the cradle support assembly and the top
skin forming an aerodynamic profile.
13. The airframe as recited in claim 1 wherein the wing airframe
includes a forward spar and an aft spar; wherein the forward wing
support has a bottom edge and an aft edge, the bottom edge coupled
to the fore-aft overhead beam and the aft edge coupled to the
forward spar; and wherein the aft wing support has a bottom edge
and a forward edge, the bottom edge coupled to the fore-aft
overhead beam and the forward edge coupled to the aft spar.
14. The airframe as recited in claim 1 wherein the wing-fuselage
integrated airframe beam assembly forms a generally vertical plane
extending longitudinally relative to the tiltrotor aircraft.
15. A tiltrotor aircraft comprising: a fuselage supported by a
fuselage airframe, the fuselage airframe including first and second
fore-aft overhead beams; a wing coupled to the fuselage and
supported by a wing airframe, the wing airframe including first and
second ribs; a first cradle support assembly including a first
forward wing support coupled to the first fore-aft overhead beam
and the wing airframe and a first aft wing support coupled to the
first fore-aft overhead beam and the wing airframe; and a second
cradle support assembly including a second forward wing support
coupled to the second fore-aft overhead beam and the wing airframe
and a second aft wing support coupled to the second fore-aft
overhead beam and the wing airframe; wherein, the first rib, the
first fore-aft overhead beam, the first forward wing support and
the first aft wing support are substantially aligned to form a
first wing-fuselage integrated airframe beam assembly and the
second rib, the second fore-aft overhead beam, the second forward
wing support and the second aft wing support are substantially
aligned to form a second wing-fuselage integrated airframe beam
assembly, the wing-fuselage integrated airframe beam assemblies
supporting the wing.
16. The tiltrotor aircraft as recited in claim 15 wherein the first
and second wing-fuselage integrated airframe beam assemblies
further comprise left and right wing-fuselage integrated airframe
beam assemblies, respectively.
17. The tiltrotor aircraft as recited in claim 15 wherein the
fuselage airframe forms a door opening having a forward edge and an
aft edge at least partially underneath the wing airframe and
wherein the first cradle support assembly extends forward of the
forward edge of the door opening and aft of the aft edge of the
door opening.
18. The tiltrotor aircraft as recited in claim 15 wherein the wing
further comprises first and second outboard ends respectively
having first and second propulsion assemblies coupled thereto and
subject to aeroelastic movement in forward flight, and wherein the
wing is subject to deflection in response to aeroelastic movement
of the first and second propulsion assemblies, the wing-fuselage
integrated airframe beam assemblies reducing deflection of the
wing.
19. The tiltrotor aircraft as recited in claim 15 wherein the
wing-fuselage integrated airframe beam assemblies increase pitch
stiffness of the wing.
20. The tiltrotor aircraft as recited in claim 15 wherein the
wing-fuselage integrated airframe beam assemblies are substantially
parallel to one another.
Description
TECHNICAL FIELD OF THE DISCLOSURE
[0001] The present disclosure relates, in general, to wing mount
assemblies for tiltrotor aircraft having a forward flight mode and
a vertical takeoff and landing flight mode and, in particular, to
airframe beam assemblies integrating the wing and fuselage of a
tiltrotor aircraft to provide structural support thereto.
BACKGROUND
[0002] Tiltrotor aircraft typically include multiple propulsion
assemblies that are positioned near the outboard ends of a wing.
Each propulsion assembly may include an engine and transmission
that provide torque and rotational energy to a drive shaft that
rotates a proprotor assembly including a hub assembly and a
plurality of proprotor blades. Typically, a pylon assembly, which
includes the proprotor assembly, is rotatable relative to the wing
such that the proprotor blades have a generally horizontal plane of
rotation providing vertical lift for takeoff, hovering and landing,
much like a conventional helicopter, and a generally vertical plane
of rotation providing forward thrust for cruising in forward flight
with the wing providing lift, much like a conventional propeller
driven airplane. In addition, tiltrotor aircraft can be operated in
configurations between the helicopter flight mode and the airplane
flight mode, which may be referred to as conversion flight
mode.
[0003] Physical structures have natural frequencies of vibration
that can be excited by forces applied thereto as a result of
operating parameters and/or environmental conditions. These
frequencies are determined, at least in part, by the materials and
geometrical dimensions of the structures. In the case of tiltrotor
aircraft, certain structures having critical natural frequencies
include the fuselage, the wing and various elements of the
propulsion assemblies. An important environmental condition
experienced by tiltrotor aircraft is forward airspeed, which may
induce proprotor aeroelastic instability, such as proprotor whirl
flutter, which may couple to the wing of a tiltrotor aircraft. In
the event of such coupling, the wing can become unstable, leading
to excessive vibration, flutter or structural failure. To prevent
such coupling, most wing airframes are designed to be stiff and
light. For example, the wing of a conventional tiltrotor aircraft
may include a torque box that is structurally suited to absorb wing
deflections and help ensure wing stability. Nonetheless, it has
been found that forward airspeed-induced proprotor aeroelastic
instability is a limiting factor relating to the maximum airspeed
of tiltrotor aircraft in forward flight mode.
[0004] In current aircraft, the wing and fuselage are separate
structures that, while physically linked, are not integrated with
one another. In addition, wings are typically mounted to the
fuselage without supporting structure designed to distribute wing
loads across an enlarged area of the fuselage airframe, thus
subjecting the area of the fuselage adjacent or directly underneath
the wing to excessive loads. Further, such loads on the fuselage
may be exacerbated by aeroelastic instability-induced wing
deflections and can become particularly problematic if structurally
weakening features, such as a door opening, are positioned
underneath the wing.
SUMMARY
[0005] In a first aspect, the present disclosure is directed to an
airframe for a tiltrotor aircraft including a wing airframe
including a rib, a fuselage airframe including a fore-aft overhead
beam and a cradle support assembly. The cradle support assembly
includes a forward wing support coupled to the fore-aft overhead
beam and the wing airframe and an aft wing support coupled to the
fore-aft overhead beam and the wing airframe. The rib, the fore-aft
overhead beam, the forward wing support and the aft wing support
are substantially aligned to form a wing-fuselage integrated
airframe beam assembly to support the wing airframe.
[0006] In some embodiments, the wing airframe may include a forward
spar, an aft spar, a top skin, a bottom skin and a plurality of
ribs to form a torque box structure. In certain embodiments, the
wing-fuselage integrated airframe beam assembly may form a
generally vertical plane with the side wall of the fuselage
airframe. In some embodiments, the fuselage airframe may form a
door opening underneath the wing airframe. In certain embodiments,
the cradle support assembly may extend at least as forward as the
forward edge of the door opening and at least as aft as the aft
edge of the door opening. In some embodiments, the wing airframe
may include a plurality of ribs spaced spanwise along the wing
airframe, and the rib of the wing-fuselage integrated airframe beam
assembly may be proximate one of the outboard edges of the fuselage
airframe. In certain embodiments, the cradle support assembly may
include wing contour ridges protruding vertically from the fore-aft
overhead beam. In some embodiments, the wing contour ridges may be
integral with the fore-aft overhead beam. In certain embodiments,
the cradle support assembly may include one or more shear ties
coupling an underside of the wing airframe to the fore-aft overhead
beam.
[0007] In some embodiments, the cradle support assembly may have a
top side forming a beam cap. In certain embodiments, the cradle
support assembly may include one or more support straps coupling
the beam cap to the top skin of the wing airframe. In some
embodiments, the top side of the cradle support assembly and the
top skin of the wing airframe may form an aerodynamic profile. In
certain embodiments, the bottom edge of the forward wing support
may be coupled to the fore-aft overhead beam and the aft edge of
the forward wing support may be coupled to the forward spar of the
wing airframe. In some embodiments, the bottom edge of the aft wing
support may be coupled to the fore-aft overhead beam and the
forward edge of the aft wing support may be coupled to the aft spar
of the wing airframe. In certain embodiments, the wing-fuselage
integrated airframe beam assembly may form a generally vertical
plane extending longitudinally relative to the tiltrotor
aircraft.
[0008] In a second aspect, the present disclosure is directed to a
tiltrotor aircraft including a fuselage supported by a fuselage
airframe. The fuselage airframe includes first and second fore-aft
overhead beams. The tiltrotor aircraft includes a wing coupled to
the fuselage and supported by a wing airframe. The wing airframe
includes first and second ribs. The tiltrotor aircraft includes a
first cradle support assembly including a first forward wing
support coupled to the first fore-aft overhead beam and the wing
airframe and a first aft wing support coupled to the first fore-aft
overhead beam and the wing airframe. The tiltrotor aircraft
includes a second cradle support assembly including a second
forward wing support coupled to the second fore-aft overhead beam
and the wing airframe and a second aft wing support coupled to the
second fore-aft overhead beam and the wing airframe. The first rib,
the first fore-aft overhead beam, the first forward wing support
and the first aft wing support are substantially aligned to form a
first wing-fuselage integrated airframe beam assembly and the
second rib, the second fore-aft overhead beam, the second forward
wing support and the second aft wing support are substantially
aligned to form a second wing-fuselage integrated airframe beam
assembly, the wing-fuselage integrated airframe beam assemblies
supporting the wing.
[0009] In some embodiments, the first and second wing-fuselage
integrated airframe beam assemblies may include left and right
wing-fuselage integrated airframe beam assemblies, respectively. In
certain embodiments, the wing may be subject to deflection in
response to the aeroelastic movement of propulsion assemblies
coupled thereto, and the wing-fuselage integrated airframe beam
assemblies may reduce deflection of the wing. In some embodiments,
the wing-fuselage integrated airframe beam assemblies may increase
pitch stiffness of the wing. In certain embodiments, the
wing-fuselage integrated airframe beam assemblies may be
substantially parallel to one another. In some embodiments, the
wing-fuselage integrated airframe beam assemblies may extend
longitudinally relative to the fuselage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the features and
advantages of the present disclosure, reference is now made to the
detailed description along with the accompanying figures in which
corresponding numerals in the different figures refer to
corresponding parts and in which:
[0011] FIGS. 1A-1C are schematic illustrations of a tiltrotor
aircraft having an integrated wing mount assembly in accordance
with embodiments of the present disclosure;
[0012] FIG. 2 is a side view of a wing-fuselage integrated airframe
beam assembly mounted over a door opening in accordance with
embodiments of the present disclosure;
[0013] FIG. 3 is an isometric view of an integrated wing mount
assembly in accordance with embodiments of the present
disclosure;
[0014] FIGS. 4A-4E are various views of an integrated wing mount
assembly in accordance with embodiments of the present
disclosure;
[0015] FIG. 5 is an isometric view of a fuselage airframe having
fore-aft overhead beams including integral wing contour ridges in
accordance with embodiments of the present disclosure; and
[0016] FIG. 6 is an isometric view of an integrated wing mount
assembly in accordance with embodiments of the present
disclosure.
DETAILED DESCRIPTION
[0017] While the making and using of various embodiments of the
present disclosure are discussed in detail below, it should be
appreciated that the present disclosure provides many applicable
inventive concepts, which can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative and do not delimit the scope of the present
disclosure. In the interest of clarity, all features of an actual
implementation may not be described in this specification. It will
of course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developer's specific goals, such as compliance with
system-related and business-related constraints, which will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0018] In the specification, reference may be made to the spatial
relationships between various components and to the spatial
orientation of various aspects of components as the devices are
depicted in the attached drawings. However, as will be recognized
by those skilled in the art after a complete reading of the present
disclosure, the devices, members, apparatuses, and the like
described herein may be positioned in any desired orientation.
Thus, the use of terms such as "above," "below," "upper," "lower"
or other like terms to describe a spatial relationship between
various components or to describe the spatial orientation of
aspects of such components should be understood to describe a
relative relationship between the components or a spatial
orientation of aspects of such components, respectively, as the
devices described herein may be oriented in any desired direction.
As used herein, the term "coupled" may include direct or indirect
coupling by any means, including by mere contact or by moving
and/or non-moving mechanical connections.
[0019] Referring to FIGS. 1A-1C in the drawings, a tiltrotor
aircraft is schematically illustrated and generally designated 10.
Tiltrotor aircraft 10 includes a fuselage 12 and a tail assembly 14
having control surfaces operable for horizontal and/or vertical
stabilization during forward flight. A wing 16 is supported by an
integrated wing mount assembly 18 that may be either fixed or
rotate relative to fuselage 12 to enable tiltrotor aircraft 10 to
convert to a storage configuration. Together, fuselage 12, tail
assembly 14 and wing 16 as well as their various frames, supports,
longerons, stringers, bulkheads, spars, ribs, including ribs 20a,
20b, and skins, including wing skin assembly 22, may be considered
to be the airframe of tiltrotor aircraft 10. The airframe of
tiltrotor aircraft 10 includes a wing airframe 24 including spars,
ribs 20a, 20b and wing skin assembly 22, and a fuselage airframe 26
including fore-aft overhead beams 28a, 28b and a fuselage skin
assembly 30. Integrated wing mount assembly 18 integrates, or
fuses, wing airframe 24 with fuselage airframe 26 to form left and
right wing-fuselage integrated airframe beam assemblies 32a, 32b,
which strengthen the structural integrity of both fuselage 12 and
wing 16.
[0020] Coupled to the outboard ends of wing 16 are propulsion
assemblies 34a, 34b. Propulsion assemblies 34a, 34b include fixed
nacelles 36a, 36b, respectively, each of which preferably houses an
engine and a fixed portion of a drive system. A pylon assembly 38a
is rotatable relative to fixed nacelle 36a and wing 16 between a
generally horizontal orientation, as best seen in FIG. 1A, and a
generally vertical orientation, as best seen in FIG. 1B. Pylon
assembly 38a includes a rotatable portion of the drive system and a
proprotor assembly 40a that is rotatable responsive to torque and
rotational energy provided via the engine and drive system.
Likewise, a pylon assembly 38b is rotatable relative to fixed
nacelle 36b and wing 16 between a generally horizontal orientation,
as best seen in FIG. 1A, and a generally vertical orientation, as
best seen in FIG. 1B. Pylon assembly 38b includes a rotatable
portion of the drive system and a proprotor assembly 40b that is
rotatable responsive to torque and rotational energy provided via
the engine and drive system. In the illustrated embodiment,
proprotor assemblies 40a, 40b each include three proprotor blade
assemblies 42. It should be understood by those having ordinary
skill in the art, however, that proprotor assemblies 40a, 40b could
alternatively have a different number of proprotor blades, either
less than or greater than three. In addition, it should be
understood that the position of pylon assemblies 38a, 38b, the
angular velocity or revolutions per minute (RPM) of proprotor
assemblies 40a, 40b, the pitch of proprotor blades 42 and the like
are controlled by the pilot of tiltrotor aircraft 10 and/or the
flight control system to selectively control the direction, thrust
and lift of tiltrotor aircraft 10 during flight.
[0021] FIG. 1A illustrates tiltrotor aircraft 10 in a forward
flight mode or airplane flight mode, in which proprotor assemblies
40a, 40b are positioned to rotate in a substantially vertical plane
to provide a forward thrust while a lifting force is supplied by
wing 16 such that tiltrotor aircraft 10 flies much like a
conventional propeller driven aircraft. FIG. 1B illustrates
tiltrotor aircraft 10 in a vertical takeoff and landing (VTOL)
flight mode or helicopter flight mode, in which proprotor
assemblies 40a, 40b are positioned to rotate in a substantially
horizontal plane to provide a vertical thrust such that tiltrotor
aircraft 10 flies much like a conventional helicopter. During
operation, tiltrotor aircraft 10 may convert from helicopter flight
mode to airplane flight mode following vertical takeoff and/or
hover. Likewise, tiltrotor aircraft 10 may convert back to
helicopter flight mode from airplane flight mode for hover and/or
vertical landing. In addition, tiltrotor aircraft 10 can perform
certain flight maneuvers with proprotor assemblies 40a, 40b
positioned between airplane flight mode and helicopter flight mode,
which can be referred to as conversion flight mode.
[0022] Preferably, each fixed nacelle 36a, 36b houses a drive
system, such as an engine and transmission, for supplying torque
and rotational energy to a respective proprotor assembly 40a, 40b.
In such embodiments, the drive systems of each fixed nacelle 36a,
36b may be coupled together via one or more drive shafts located in
wing 16 such that either drive system can serve as a backup to the
other drive system in the event of a failure. Alternatively or
additionally, fuselage 12 may include a drive system, such as an
engine and transmission, for providing torque and rotational energy
to each proprotor assembly 40a, 40b via one or more drive shafts
located in wing 16. In tiltrotor aircraft having both nacelle and
fuselage mounted drive systems, the fuselage mounted drive system
may serve as a backup drive system in the event of failure of
either or both of the nacelle mounted drive systems.
[0023] During high speed operations in airplane flight mode, the
forward airspeed of tiltrotor aircraft 10 may induce proprotor
aeroelastic movement or instability, such as propeller whirl
flutter, which may couple to wing 16 and lead to failures. The
aeroelastic movement of propulsion assemblies 34a, 34b, and of
pylon assemblies 38a, 38b in particular, may be caused by
aeroelastic phenomena, including dynamic aeroelastic phenomena,
which involves interactions among inertial, aerodynamic and elastic
forces, and/or static aeroelastic phenomena, which involve
interactions between aerodynamic and elastic forces. The
flexibility of modern aircraft is responsible, at least in part,
for the various types of aeroelastic phenomena. Aeroelastic
phenomena arise when structural deformations or movements in
aircraft components induce additional aerodynamic forces. These
additional aerodynamic forces may produce additional structural
deformations or movements that induce still greater aerodynamic
forces. Such interactions may tend to become smaller over time
until a condition of stable equilibrium is reached, or they may
tend to diverge, which can destroy the structure.
[0024] Left and right wing-fuselage integrated airframe beam
assemblies 32a, 32b each include a cradle support assembly 56a, 56b
into which ribs 20a, 20b are mounted, respectively. Rib 20a, cradle
support assembly 56a and fore-aft overhead beam 28a are
substantially aligned and integrated into a web-like structure to
form left wing-fuselage integrated airframe beam assembly 32a. Rib
20b, cradle support assembly 56b and fore-aft overhead beam 28b are
substantially aligned and integrated into a web-like structure to
form right wing-fuselage integrated airframe beam assembly 32b. As
best seen in FIG. 1C, fuselage airframe 26 includes side walls 58a,
58b, which may be formed from fuselage skin assembly 30, beams,
panels and/or other structural components. Wing-fuselage integrated
airframe beam assemblies 32a, 32b each form generally vertical
planes with side walls 58a, 58b of fuselage airframe 26,
respectively, thereby enhancing the structural integrity of
fuselage 12 and wing 16. In addition, while wing airframe 24 may
include any number of ribs, ribs 20a, 20b, which form part of
wing-fuselage integrated airframe beam assemblies 32a, 32b, are
proximate or directly above outboard edges 60a, 60b of fuselage
airframe 26, respectively. Left and right wing-fuselage integrated
airframe beam assemblies 32a, 32b are substantially parallel to one
another and form generally vertical planes extending longitudinally
relative to tiltrotor aircraft 10.
[0025] By integrating wing airframe 24 with fuselage airframe 26,
wing-fuselage integrated airframe beam assemblies 32a, 32b provide
support for wing 16, including by stabilizing wing 16 against wing
deflections caused by aeroelastic phenomena or instability of
propulsion assemblies 34a, 34b. Wing-fuselage integrated airframe
beam assemblies 32a, 32b provide a stiff wing pitch restraint that
reduces pitching and/or twisting of wing 16 resulting from such
aeroelastic phenomena as well as other causes. By increasing the
pitch stiffness of center portion 62 of wing 16, wing-fuselage
integrated airframe beam assemblies 32a, 32b also protect the
structural integrity of the portion of fuselage 12 underneath wing
16, which in the illustrated embodiment is structurally compromised
due to the presence of a door opening 64. Wing-fuselage integrated
airframe beam assemblies 32a, 32b also help to support the weight
of wing 16 itself.
[0026] It should be appreciated that tiltrotor aircraft 10 is
merely illustrative of a variety of aircraft that can implement the
embodiments disclosed herein. Indeed, wing-fuselage integrated
airframe beam assemblies 32a, 32b may be utilized on any aircraft
having one or more wings. Other aircraft implementations can
include hybrid aircraft, tiltwing aircraft, quad tiltrotor
aircraft, unmanned aircraft, gyrocopters, airplanes, jets and the
like. As such, those of ordinary skill in the art will recognize
that wing-fuselage integrated airframe beam assemblies 32a, 32b can
be integrated into a variety of aircraft configurations. Although
wing-fuselage integrated airframe beam assemblies 32a, 32b are
illustrated as being implemented on a unitary wing that spans both
sides of fuselage 12, wing-fuselage integrated airframe beam
assemblies 32a, 32b may be utilized in two or more structurally
separate or semi-separate wings of the same aircraft. It should be
appreciated that even though aircraft are particularly well-suited
to implement the embodiments of the present disclosure,
non-aircraft vehicles and devices can also implement the
embodiments, including, but not limited to, automobiles or
land-based vehicles.
[0027] Referring to FIG. 2 in the drawings, an integrated wing
mount assembly is schematically illustrated and generally
designated 100. Fuselage airframe 102 forms door opening 104
underneath wing airframe 106. Depending on the particular aircraft,
door opening 104 may be fully or partially underneath wing airframe
106. Door opening 104 may be considered a structural weakness that
increases the fuselage airframe's vulnerability to loads applied
thereon, including the weight of the wing and wing deflection
caused by aeroelastic phenomena. FIG. 2 illustrates left
wing-fuselage integrated airframe beam assembly 108a, including
cradle support assembly 110a. Forward edge 112 of cradle support
assembly 110a extends forward of forward edge 114 of door opening
104 and aft edge 116 of cradle support assembly 110a extends aft of
aft edge 118 of door opening 104, thus providing adequate support
for the wing and structural reinforcement for fuselage airframe
102. Integrated wing mount assembly 100 distributes the load of the
wing over a longitudinal span 120 of fuselage airframe 102 that is
longer than a longitudinal length 122 of door opening 104. In other
embodiments, longitudinal span 120 of cradle support assembly 110a
may be any length equal to or greater than longitudinal length 122
of door opening 104.
[0028] Rib 124a, cradle support assembly 110a and fore-aft overhead
beam 126a are fused, integrated or otherwise coupled in any manner
to form wing-fuselage integrated airframe beam assembly 108a.
Wing-fuselage integrated airframe beam assembly 108a has an upper
beam portion 128 that includes rib 124a and cradle support assembly
110a. Wing-fuselage integrated airframe beam assembly 108a also has
a lower beam portion 130 that includes fore-aft overhead beam 126a
of fuselage airframe 102. Thus, wing-fuselage integrated airframe
beam assembly 108a integrates portions of both wing airframe 106
(e.g., rib 124a) and fuselage airframe 102 (e.g., fore-aft overhead
beam 126a) into a tall, deep and efficient beam providing
sufficient stiffness to carry the bending, twisting and other
deflection motions of the wing across and beyond longitudinal
length 122 of door opening 104. In some embodiments, wing-fuselage
integrated airframe beam assembly 108a may have a height 132 in a
range between 20 and 40 inches, such as approximately 30 inches.
Depending on the particular aircraft, door opening 104 may be on
either or both sides of fuselage airframe 102.
[0029] Referring to FIGS. 3, 4A-4E and 5 in the drawings, left and
right wing-fuselage integrated airframe beam assemblies 108a, 108b
of integrated wing mount assembly 100 are shown in various views.
Right wing-fuselage integrated airframe beam assembly 108b is
substantially similar to left wing-fuselage integrated airframe
beam assembly 108a. For sake of efficiency, certain features were
disclosed in FIG. 2 only with regard to left wing-fuselage
integrated airframe beam assembly 108a. One having ordinary skill
in the art, however, will fully appreciate an understanding of
right wing-fuselage integrated airframe beam assembly 108b based
upon the disclosure of left wing-fuselage integrated airframe beam
assembly 108a. Wing airframe 106, which supports wing 134, forms a
torque box structure 136 made up of forward spar 138, aft spar 140,
top skin 142, bottom skin 144 and a plurality of ribs 124 such as
ribs 124a, 124b, as well as other structural elements. Torque box
136 is configured to distribute loads, shears and other motions
generated by the propulsion assemblies during the various flight
modes.
[0030] Cradle support assemblies 110a, 110b each include forward
wing supports 146a, 146b, aft wing supports 148a, 148b and wing
contour ridges 150a, 150b, respectively. Wing contour ridges 150a,
150b protrude vertically from the top sides of fore-aft overhead
beams 126a, 126b, respectively. Wing contour ridges 150a, 150b may
be either integral with or separate components from fore-aft
overhead beams 126a, 126b, respectively. Forward wing supports
146a, 146b have bottom edges 152a, 152b coupled to fore-aft
overhead beams 126a, 126b via wing contour ridges 150a, 150b,
respectively. In other embodiments, bottom edges 152a, 152b may
couple directly to fore-aft overhead beams 126a, 126b,
respectively. Forward wing supports 146a, 146b have aft edges 154a,
154b coupled to ribs 124a, 124b via forward spar 138, respectively.
In other embodiments, aft edges 154a, 154b may couple directly to
ribs 124a, 124b, respectively. Aft wing supports 148a, 148b have
bottom edges 156a, 156b coupled to fore-aft overhead beams 126a,
126b via wing contour ridges 150a, 150b, respectively. In other
embodiments, bottom edges 156a, 156b may couple directly to
fore-aft overhead beams 126a, 126b, respectively. Aft wing supports
148a, 148b have forward edges 158a, 158b coupled to ribs 124a, 124b
via aft spar 140, respectively. In other embodiments, forward edges
158a, 158b may couple directly to ribs 124a, 124b, respectively.
While forward and aft wing supports 146a, 146b, 148a, 148b are
shown as separate components from wing contour ridges 150a, 150b,
in other embodiments forward and aft wing supports 146a, 148a may
be integral with wing contour ridge 150a and forward and aft wing
supports 146b, 148b may be integral with wing contour ridge 150b.
Forward and aft wing supports 146a, 148a may be horizontally and
longitudinally aligned relative to one another, as illustrated.
Likewise, forward and aft wing supports 146b, 148b may be
horizontally and longitudinally aligned relative to one
another.
[0031] The top sides of cradle support assemblies 110a, 110b form
beam caps 160a, 160b, respectively. In particular, beam cap 160a is
formed from the top sides of wing contour ridge 150a, forward wing
support 146a and aft wing support 148a. Beam cap 160b is formed
from the top sides of wing contour ridge 150b, forward wing support
146b and aft wing support 148b. Beam caps 160a, 160b enhance the
structural integrity of wing-fuselage integrated airframe beam
assemblies 108a, 108b, respectively. Cradle support assembly 110a
includes support straps 162a, 164a coupling beam cap 160a to top
skin 142. Likewise, cradle support assembly 110b includes support
straps 162b, 164b to couple beam cap 160b to top skin 142. Support
straps 162a, 162b, 164a, 164b transfer load from beam caps 160a,
160b to top skin 142, thereby effectively allowing the load of beam
caps 160a, 160b to pass across the top of wing 134. Lower beam caps
166a, 166b of fore-aft overhead beams 126a, 126b provide a strong
bottom boundary at the top of door opening 104 so that
wing-fuselage integrated airframe beam assemblies 108a, 108b act as
tall, stiff and efficient beam structures for supporting wing 134,
respectively. In this manner, left wing-fuselage integrated
airframe beam assembly 108a, formed from aligned and integrated
components rib 124a, fore-aft overhead beam 126a, forward wing
support 146a and aft wing support 148a, and right wing-fuselage
integrated airframe beam assembly 108b, formed from aligned and
integrated components rib 124b, fore-aft overhead beam 126b,
forward wing support 146b and aft wing support 148b, each extend
longitudinally relative to the fuselage to support wing 134 against
aeroelastic-induced deflections and protect the structural
integrity of fuselage airframe 102, including door opening 104.
[0032] To transfer shear along the bottom of wing 134 and provide
additional support thereto, cradle support assemblies 110a, 110b
may each include one or more shear ties, or clips, 168a, 168b
coupling the underside of wing airframe 106, including ribs 124a,
124b, to fore-aft overhead beams 126a, 126b, respectively. Shear
ties 168a, 168b are illustrated as being coupled to fore-aft
overhead beams 126a, 126b via wing contour ridges 150a, 150b, but
in other embodiments shear ties 168a, 168b may be directly coupled
to fore-aft overhead beams 126a, 126b, respectively. Forward and
aft wing supports 146a, 146b, 148a, 148b each have a generally
triangular shape so that the top sides of cradle support assemblies
110a, 110b and top skin 142 form an aerodynamic profile, which may
be covered by a fairing. Forward and aft wing supports 146a, 146b,
148a, 148b, however, may have any shape or size suitable for
supporting wing 134 and integrating into a beam structure.
Integrated wing mount assembly 100 also includes lateral support
struts 170 to provide lateral support to left and right
wing-fuselage integrated airframe beam assemblies 108a, 108b. While
lateral support struts 170 are illustrated as being forward of
torque box 136, lateral support struts 170 may be located at either
or both of the forward or aft sides of torque box 136. In other
embodiments, integrated wing mount assembly 100 may include no
lateral support struts at all.
[0033] Referring to FIG. 6 in the drawings, an integrated wing
mount assembly is schematically illustrated and generally
designated 200. In integrated wing mount assembly 200, forward wing
supports have been replaced by forward strut assemblies 202a, 202b.
Each forward strut assembly 202a, 202b includes a strut post 204a,
204b, respectively, oriented vertically and coupled to forward spar
206. One end of each strut 208a, 208b couples to the tops of strut
posts 204a, 204b, and the other end of each strut 208a, 208b
couples to fore-aft overhead beams 210a, 210b, respectively. Struts
208a, 208b may act as the caps of a beam, similar to beam caps
160a, 160b above, to provide suitable pitch stiffness for the wing.
While forward strut assemblies 202a, 202b are illustrated as
replacing forward wing supports, forward strut assemblies 202a,
202b may replace either or both of forward wing supports or aft
wing supports 212a, 212b. Struts 208a, 208b may each have a static
or variable length depending on the embodiment. In other
embodiments, struts 208a, 208b may be tunable to provide an
adjustable and desired stiffness for the wing, as by, for example,
utilizing a damper or elastomer or tailoring the strut
geometry.
[0034] The foregoing description of embodiments of the disclosure
has been presented for purposes of illustration and description. It
is not intended to be exhaustive or to limit the disclosure to the
precise form disclosed, and modifications and variations are
possible in light of the above teachings or may be acquired from
practice of the disclosure. The embodiments were chosen and
described in order to explain the principals of the disclosure and
its practical application to enable one skilled in the art to
utilize the disclosure in various embodiments and with various
modifications as are suited to the particular use contemplated.
Other substitutions, modifications, changes and omissions may be
made in the design, operating conditions and arrangement of the
embodiments without departing from the scope of the present
disclosure. Such modifications and combinations of the illustrative
embodiments as well as other embodiments will be apparent to
persons skilled in the art upon reference to the description. It
is, therefore, intended that the appended claims encompass any such
modifications or embodiments.
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